Display device and method of manufacturing the same

ABSTRACT

A display device and a method of manufacturing the display device are provided. The display device includes a substrate; a driving voltage line disposed on the substrate; a driving voltage line pad to transmit a driving voltage to the driving voltage line; a driving transistor connected to the driving voltage line; a pixel electrode connected to the driving transistor; a common electrode opposing the pixel electrode; a light emitting member disposed between the pixel electrode and the common electrode; and a common electrode pad disposed on the substrate so as to transmit a common voltage to the common electrode. The common electrode pad and the driving voltage line pad are exposed at a side surface of the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2005-0102590, filed on Oct. 28, 2005, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device and a method ofmanufacturing the display device.

2. Discussion of the Background

Recently, lighter and thinner monitors and television sets have beenrequired. With this requirement, cathode ray tubes (CRTs) have beenreplaced with flat panel display devices such as liquid crystal displays(LCDs).

However, since an LCD may require a backlight unit to display an image,it may have a slow response speed and narrow viewing angle.

Since an organic light emitting display (OLED) does not have suchproblems, it is attracting increasing attention.

Generally, an OLED display includes a light emitting layer interposedbetween two electrodes. Electrons injected from one electrode and holesinjected from the other electrode combine to form excitons, which emitenergy and light.

Since the OLED display does not require an additional light source suchas the backlight unit, the OLED display may have advantages of low powerconsumption, fast response speed, wide viewing angle, and high contrastratio.

An OLED display may be a passive matrix or active matrix displaydepending upon its driving method.

The passive matrix display has a simple structure in which light emitsfrom a region where two electrodes cross each other. On the other hand,the active matrix display has a structure in which light emits bycurrent-driven pixels using thin film transistors (TFTs).

The active matrix OLED display may be a bottom emission type and/or atop emission type depending upon its light emission method. The bottomemission type display emits light toward a substrate where the TFTs areformed, and the top emission type display emits light away from thesubstrate where the TFTs are formed.

The bottom emission type display may have a low aperture ratio sincelight cannot pass through a portion where its TFTs and wires are formed.On the other hand, the top emission type display may have a highaperture ratio since the light emitting region is not associated withthe space occupied by the TFTs and wires.

The above information disclosed in this background section is only forenhancement of understanding of the background of the present inventionand therefore it may contain information that does not form the priorart that is already known in this country to a person of ordinary skillin the art.

SUMMARY OF THE INVENTION

The present invention provides a display and a method of manufacturingthe display that may prevent accumulation of charges on the commonelectrode during the manufacturing processes.

Additional features of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention.

The present invention discloses a display device including a substrate,a driving voltage line disposed on the substrate, and a driving voltageline pad to receive and transmit a driving voltage to the drivingvoltage line. A driving transistor is connected to the driving voltageline, a pixel electrode is connected to the driving transistor, and acommon electrode opposes the pixel electrode. A light emitting member isdisposed between the pixel electrode and the common electrode, and acommon electrode pad is formed on the substrate so as to transmit acommon voltage to the common electrode. Portions of the common electrodepad and the driving voltage line pad are exposed at a side surface ofthe substrate.

The present invention also discloses a method of manufacturing a displaydevice including forming a plurality of gate lines, a driving voltageline including a driving voltage line pad, a plurality of data lines,and a common electrode pad on a substrate. A first connecting member isformed between the driving voltage line pad and the common electrodepad, and a protective film and a pixel electrode are formed on the gatelines, the driving voltage line, and the data lines. A light emittinglayer is formed on the pixel electrode, a common electrode is formed onthe light emitting layer, a sealing member is formed on the commonelectrode, and the substrate is cut.

The present invention also discloses a method of manufacturing a displaydevice including forming a plurality of gate lines, a driving voltageline including a driving voltage line pad, a plurality of data lines,and a common electrode pad on a substrate. A discharge member is formedconnected to the common electrode pad, and a protective film and a pixelelectrode are formed on the gate lines, the driving voltage line, andthe data lines. A light emitting layer is formed on the pixel electrode,and a common electrode is formed on the light emitting layer. A sealingmember is formed on the common electrode, and the substrate is cut.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a block diagram showing a display device according to anexemplary embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram showing a display deviceaccording to an exemplary embodiment of the present invention.

FIG. 3A is a view showing a layout of a display device on a basesubstrate according to an exemplary embodiment of the present invention.

FIG. 3B is a view showing a layout of the display device of FIG. 3A.

FIG. 3C is a cross-sectional view taken along line III-III of FIG. 3B.

FIG. 4 is a view showing a portion of a layout of a display deviceaccording to another exemplary embodiment of the present invention.

FIG. 5 is a view showing a portion of a layout of a display deviceaccording to another exemplary embodiment of the present invention.

FIG. 6 is a view showing a layout of the display device according toanother exemplary embodiment of the present invention.

FIG. 7 and FIG. 8 are cross sectional views taken along lines VII-VIIand VIII-VIII of FIG. 6, respectively.

FIG. 9 is a view showing a layout of a display device according toanother exemplary embodiment of the present invention.

FIG. 10, FIG. 11, and FIG. 12 are cross-sectional views taken alonglines X-X, XI-XI, and XII-XII of FIG. 9, respectively.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which embodiments of the invention are shown.This invention may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure isthorough, and will fully convey the scope of the invention to thoseskilled in the art. In the drawings, the size and relative sizes oflayers and regions may be exaggerated for clarity. Like referencenumerals in the drawings denote like elements.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it can bedirectly on or directly connected to the other element or layer, orintervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on” or “directly connected to”another element or layer, there are no intervening elements or layerspresent.

In the exemplary embodiments of the present invention, the OLED displayincludes a pixel electrode and a common electrode opposing each otherand a light emitting member interposed therebetween.

According to conventional manufacturing processes, when forming thecommon electrode or performing an encapsulating process on the commonelectrode, charges may accumulate on the common electrode due toelectron injection, ion injection, or electrostatics.

When charges accumulate on the common electrode, the light emittingmember may not operate since a potential difference is generated betweenthe common electrode and the light emitting member.

Consequently, surfaces of the light emitting member, the pixelelectrode, or the common electrode may peel off, thereby deterioratingthe display device's quality.

In order to solve this problem, the present invention provides a displaydevice and a method of manufacturing the display device in which it maybe possible to prevent charge accumulation on the common electrodeduring the manufacturing processes.

FIG. 1 is a block diagram showing an OLED display according to anexemplary embodiment of the present invention, and FIG. 2 is anequivalent circuit diagram showing a pixel of the OLED display of FIG.1.

Referring to FIG. 1, the OLED display includes a display panel 300, ascanning driver 400 and data driver 500 connected to the display panel300, and a signal controller 600 that controls the drivers.

The display panel 300 includes a plurality of display signal lines G₁ toG_(n) and D₁ to D_(m), a plurality of driving voltage lines (not shown),and a plurality of pixels PX that are connected to the lines and arrayedsubstantially in a matrix.

The display signal lines G₁ to G_(n) and D₁ to D_(m) include a pluralityof gate lines G₁ to G_(n) that transmit scan signals and a plurality ofdata lines D₁ to D_(m) that transmit data voltages.

The gate lines G₁ to G_(n) extend substantially in the row direction andare separated from each other while being substantially parallel to eachother.

The data lines D₁ to D_(m) extend substantially in the column directionand are separated from each other while being substantially parallel toeach other.

The driving voltage lines transmit driving voltages Vdd to the pixelsPX.

As shown in FIG. 2, each pixel PX is connected to a gate line 121 anddata line 171, and includes an organic light emitting diode LD, adriving transistor Qd, a capacitor Cst, and a switching transistor Qs.

The driving transistor Qd is a three-port device having a control portconnected to the switching transistor Qd and the capacitor Cst, an inputport connected to a driving voltage line 172 (i.e. Vdd), and an outputport connected to the organic light emitting diode LD.

The switching transistor Qs is also a three-port device having a controlport connected to the gate line 121, an input port connected to the dataline 171, and an output port connected to the capacitor Cst and thedriving transistor Qd.

The capacitor Cst is connected between the switching transistor Qs andthe driving voltage line 172. The capacitor Cst sustains the datavoltage charged by the switching transistor Qs for a predetermined timeperiod.

The anode and cathode of the organic light emitting diode LD areconnected to the driving transistor Qd and a common voltage Vss,respectively.

The organic light emitting diode LD emits light with differentintensities according to an amount of a current I_(LD) supplied by thedriving transistor Qd to display an image.

The amount of the current I_(LD) depends on a magnitude of a voltage Vgsbetween the control port and the input port of the driving transistorQd.

The switching and driving transistors Qs and Qd are an n-channel fieldeffect transistors (FETs) made of an amorphous silicon or polysilicon.

Alternatively, these transistors Qs and Qd may be p-channel field effecttransistors. In this case, the operation, voltage, and current of thep-channel field effect transistors would be opposite to those of then-channel field effect transistors.

The display device of FIG. 1 will be described in detail below withreference to FIG. 3A, FIG. 3B, and FIG. 3C.

FIG. 3A is a view showing a layout of the display device formed on abase substrate according to an exemplary embodiment of the presentinvention, FIG. 3B is a view showing a layout of the display deviceafter being cut out from the base substrate of FIG. 3A, and FIG. 3C is across-sectional view taken along line IIIc-IIIc of FIG. 3B.

Referring to FIG. 3A, a base substrate 10, which may be made of atransparent glass or plastic material, includes a plurality of unitareas 20. Each unit area 20 is defined by a cutting-plane line 30.

A plurality of gate lines 121, a plurality of data lines 171, aplurality of driving voltage lines 172, and thin film transistors (notshown), which are connected to the lines 121, 171, and 172, are formedin the unit area 20.

A pixel electrode 191 is formed on the gate lines 121, the data lines171, the driving voltage lines 172, and the thin film transistor.

A light emitting member (not shown) is formed between the pixelelectrode 191 and a common electrode 270.

A gate line shorting bar 61, which connects the gate lines 121 to eachother, is formed along one periphery of the pixel electrode 191 and thecommon electrode 270, and a data line shorting bar 62, which connectsthe data lines 171 to each other, is formed along another periphery ofthe pixel electrode 191 and the common electrode 270.

A common electrode pad 279 is formed along another periphery of thepixel electrode 191 and the common electrode 270.

A portion of the common electrode pad 279 extends to serve as a contact278 for connecting the common electrode 270 thereto via contact hole187.

The common electrode pad 279 receives a common voltage Vcom andtransmits the common voltage Vcom to the common electrode 270 throughthe contact 278.

The common electrode pad 279 may be made of the same material as thegate lines 121 or the data lines 171.

A driving voltage line pad 178A, which transmits a driving voltage tothe driving voltage lines 172, is formed along another periphery of thepixel electrode 191 and the common electrode 270.

The driving voltage line pad 178A receives a driving voltage Vdd andtransmits the driving voltage Vdd to the respective driving voltagelines 172.

The driving voltage line pad 178A may be made of the same material asthe data lines 171.

A connector 76 electrically connects the common electrode pad 279 andthe driving voltage line pad 178A to each other.

When the common electrode pad 279 is made of the same material as thegate lines 121, the connector 76 may be made of a transparent conductivematerial such as indium tin oxide (ITO) or indium zinc oxide (IZO). Whenthe common electrode pad 279 is made of the same material as the datalines 171, the connector 76 may also be made of the same material as thedata lines 171.

A connector 77 electrically connects the common electrode pad 279 andthe data line shorting bar 62 to each other. A connector 78 electricallyconnects the driving voltage line pad 178A and the gate line shortingbar 61 to each other.

In addition to the gate line shorting bar 61 and the data line shortingbar 62, the common electrode pad 279 or the driving voltage line pad178A may also be connected to another portion that connects the gatelines 121 or the data lines 171 to each other.

The positions of the common electrode pad 279 and the driving voltageline pad 178A may be changed with each other. Hence, the connectionalrelationship with the shorting bars 61 and 62 may accordingly vary.

By electrically connecting the common electrode pad 279 to the gate lineshorting bar 61, the data line shorting bar 62 and the driving voltageline pad 178A, it is possible to move charges generated in the commonelectrode 270 to another connection channel.

With such an arrangement, it may be possible to minimize failure causedby the charges in the common electrode 270.

Hereinafter, a method of manufacturing the display device according toan exemplary embodiment of the present invention will be described indetail below with reference to FIG. 3A, FIG. 3B, and FIG. 3C.

As shown in FIG. 3A, metal films may be sequentially stacked on the basesubstrate 10 for each unit area 20 by performing a sputtering process orthe like. The metal films are then subject to a photolithography processto form a gate conductor including the gate lines 121, the gate lineshorting bar 61, and the common electrode pad 279.

Next, a gate insulating layer (not shown) and a plurality ofsemiconductors (not shown) are formed.

Thereafter, metal films are stacked by performing a sputtering processor the like, and are subject to a photolithography process to form adata conductor including the data lines 171, the driving voltage lines172, and the driving voltage line pad 178A.

An inorganic insulating material or a photosensitive insulating materialis then coated by a chemical vapor deposition process or the like toform a protective film (not shown).

The pixel electrode 191 is formed on the protective film, and theconnectors 76, 77, and 78 that connect the gate line shorting bar 61,the data line shorting bar 62, the common electrode pad 279, and thedriving voltage line pad 178A are concurrently formed.

The connectors 76, 77, and 78 extend beyond the cutting-plane line 30that defines each unit area 20.

A light emitting member (not shown) is formed on the pixel electrode191.

The common electrode 270 is formed on the light emitting member.

A sealing member (not shown) is provided on the common electrode 270,and it seals the unit areas 20.

After the sealing process, the unit areas 20 are cut along thecutting-plane line 30 to form a single display device.

At this time, the connectors 76, 77, and 78 are cut at the cutting-planeline 30.

More specifically, portions of the connectors 76, 77, and 78 inside thecutting-plane line 30 constitute portions of the gate line shorting bar61, the data line shorting bar 62, the common electrode pad 279 or thedriving voltage line pad 178A, and portions of the connectors 76, 77,and 78 outside the cutting-plane line 30 are removed.

As a result, the gate line shorting bar 61, the data line shorting bar62, the common electrode pad 279 and the driving voltage line pad 178Aare divided into first portions 61 a, 62 a, 279 a, and 178Aa, which areexposed at a side of a substrate 110, and second portions 61 b, 62 b,279 b, and 178Ab, which are not exposed at a side of the substrate 110.

The distance D1 between the second portion 279 b of the common electrodepad 279 and the substrate 110 and the distance D2 between the drivingvoltage line pad 178A and the substrate 110 may be 25 μm or less.

When the common electrode pad 279 is made of the same material as thedata conductor, the common electrode pad 279 and the data conductor maybe formed simultaneously.

Additionally, the connectors 76, 77, and 78 may be made of the samematerial as the common electrode 270 and formed at the time of formingthe common electrode 270 rather than the pixel electrode 191.

Hereinafter, a display device according to another exemplary embodimentof the present invention will be described below in detail withreference to FIG. 4.

FIG. 4 is a view showing a portion of a layout of a display deviceaccording to another exemplary embodiment of the present invention, inwhich the display device is formed on a base substrate.

Similar to the previous embodiment, the display device according to thepresent embodiment includes gate lines (not shown), data lines (notshown), driving voltage lines 172, and a thin film transistor (notshown) connected to the lines, formed on the base substrate 10.

A pixel electrode 191 is formed on the gate lines, the data lines, thedriving voltage lines 172, and the thin film transistor.

A light emitting member (not shown) is formed between the pixelelectrode 191 and a common electrode (not shown).

A common electrode pad 279 is formed along one periphery of the pixelelectrode 191.

A portion of the common electrode pad 279 extends to serve as a contact278 for connecting with the common electrode 270.

A driving voltage supply line 178 is commonly connected to the drivingvoltage lines 172, and the driving voltage supply line 178 extends to aportion neighboring the common electrode pad 279 to form the drivingvoltage line pad 178A.

In other words, unlike the display device in FIG. 3A, according to thepresent exemplary embodiment, the common electrode pad 279 and thedriving voltage line pad 178A are arranged along the same periphery ofthe pixel electrode 191.

Additionally, the display device according to the present exemplaryembodiment includes a discharge member 86 formed on the base substrate10.

The discharge member 86 is electrically connected to the commonelectrode pad 279 through the connector 79.

The discharge member 86 is connected to a ground potential, and may bemade of the same material as the gate lines, the data lines, the pixelelectrodes 191, or the common electrode 270.

Since the discharge member 86 is formed outside the cutting-plane line30 like the connectors 76, 77, and 78 of FIG. 3A, the discharge member86 is removed in the cutting process.

With such an arrangement, it is possible to discharge the chargesgenerated in the common electrode 270 to an outer space through thedischarge member 86.

Accordingly, it may be possible to minimize failures caused by thecharges generated in the common electrode 270 during the manufacturingprocesses.

Next, a display device according to another exemplary embodiment of thepresent invention will be described in detail below with reference toFIG. 5.

FIG. 5 is a view showing a portion of a layout of a display deviceaccording to another exemplary embodiment of the present invention, inwhich the display device is formed on a base substrate.

Similar to the previous embodiments, the display device according to thepresent embodiment includes gate lines (not shown), data lines (notshown), driving voltage lines 172, and a thin film transistor (notshown) connected to the lines, formed on the base substrate 10.

A pixel electrode 191 is formed on the gate lines, the data lines, thedriving voltage lines 172, and the thin film transistor.

A light emitting member (not shown) is formed between the pixelelectrode 191 and a common electrode (not shown).

A common electrode pad 279 is formed along one periphery of the pixelelectrode 191.

A portion of the common electrode pad 279 extends to serve as a contact278 for connecting with the common electrode 270.

A driving voltage supply line 178 is commonly connected to the drivingvoltage lines 172, and the driving voltage supply line 178 extends to aportion neighboring the common electrode pad 279 to form the drivingvoltage line pad 178A.

In other words, the common electrode pad 279 and the driving voltageline pad 178A are arranged along the same periphery of the pixelelectrode 191.

Unlike the display device of FIG. 4, according to the present exemplaryembodiment, the common electrode pad 279 and the driving voltage linepad 178A are electrically connected to each other through the connector79.

Since the common electrode pad 279 is formed adjacent to the drivingvoltage line pad 178A, it is possible to provide a shorter connectorthan that shown in FIG. 3A.

Additionally, similar to the embodiment of FIG. 4, the display deviceaccording to the present embodiment includes a discharge member 86formed on the base substrate 10.

However, unlike the embodiment shown in FIG. 4, the driving voltage linepad 178A is electrically connected to both the common electrode pad 279and the discharge member 86.

With such an arrangement, it is possible to discharge the chargesgenerated in the common electrode 270 to an outer space through thedischarge member 86 while spreading the charges toward the drivingvoltage lines 172. Accordingly, it may be possible to more effectivelyprevent failure caused by the charges generated in the common electrode270.

Hereinafter, a display device according to another exemplary embodimentof the present invention will be described below in detail withreference to FIG. 6, FIG. 7, and FIG. 8.

FIG. 6 is a view showing a layout of the display device according toanother exemplary embodiment of the present invention, and FIG. 7 andFIG. 8 are cross-sectional views taken along lines VII-VII and VIII-VIIIof FIG. 6, respectively.

A plurality of gate lines 121, which include a first control electrode124 a, and a plurality of gate conductors, which include a plurality ofsecond control electrodes 124 b, are disposed on a dielectric substrate110, which may be made of transparent glass or plastic materials.

The gate lines 121 mainly extend in a longitudinal direction andtransmit gate signals.

Each gate line 121 includes a wider end portion 129 for connection toother layers or an external driving circuit. The first control electrode124 a protrudes from the gate lines 121.

In the event that a scanning driver circuit (not shown) for generatinggate signals is integrated on the dielectric substrate 110, the gatelines 121 may extend to directly connect with the scanning drivercircuit.

The second control electrodes 124 b are spaced apart from the gate lines121, and as FIG. 6 shows, they include a storage electrode 127 extendingdownward, rightward, and then upward.

The gate conductors 121 and 124 b may be made of an aluminum-based metalsuch as aluminum (Al) or an aluminum alloy, a silver-based metal such assilver (Ag) or a silver alloy, a copper-based metal such as copper (Cu)or a copper alloy, a molybdenum-based metal such as molybdenum (Mo) or amolybdenum alloy, chromium (Cr), tantalum (Ta) or titanium (Ti).

However, the gate conductors 121 and 124 b may have a multi-layeredstructure including two conductive layers (not shown) that havedifferent physical properties.

One of the two conductive layers may be made of a metal having lowresistivity, for example an aluminum-based metal, a silver-based metal,or a copper-based metal, in order to reduce signal delay or voltagedrop.

Preferably, the other conductive layer may be made of a material havinggood physical, chemical, and electrical contact characteristics to othermaterials, particularly to indium tin oxide (ITO) or indium zinc oxide(IZO). For example, the other conductive layer may be made of amolybdenum-based metal, chromium, titanium, or tantalum.

Examples of the multi-layered structure include a lower chromium layerand an upper aluminum (alloy) layer, and a lower aluminum (alloy) layerand an upper molybdenum (alloy) layer.

However, the gate conductors 121 and 124 b may be made of various metalsand conductive materials.

Surfaces of the gate conductors 121 and 124 b may be slanted at anglesin the range of 30° to 80° with respect to a surface of the dielectricsubstrate 110.

A gate insulating layer 140, which may be made of silicon nitrideSiN_(x), silicon oxide SiO_(x), or the like, is formed on the gateconductors 121 and 124 b.

A plurality of first and second island-shaped semiconductors 154 a and154 b, which may be made of a hydrogenated amorphous silicon (a-Si) orpolysilicon, are formed on the gate insulating film 140.

The first and second semiconductors 154 a and 154 b are disposed on thefirst and second control electrodes 124 a and 124 b, respectively.

A plurality of first pairs of ohmic contact members 163 a and 165 a anda plurality of second pairs of ohmic contact members 163 b and 165 b areformed above the first and second semiconductors 154 a and 154 b,respectively.

The ohmic contact members 163 a, 163 b, 165 a, and 165 b areisland-shaped, and they may be made of silicide of an n+ hydrogenatedamorphous silicon or the like that are doped with n-type impurities suchas phosphorous (P).

A plurality of data conductors, which include a plurality of data lines171, a plurality of driving voltage lines 172, and a plurality of firstand second output electrodes 175 a and 175 b, are formed above the ohmiccontact members 163 a, 163 b, 165 a, and 165 b and the gate insulatinglayer 140.

The data lines 171 mainly extend in the transverse direction to crosswith the gate lines 121 and transmit data signals.

Each data line 171 includes a plurality of first input electrodes 173 a,which extend toward the first control electrode 124 a, and a wider endportion 179 for connection to other layers or an external drivingcircuit.

In the event that a data driver circuit (not shown) for generating datasignals is integrated on the dielectric substrate 110, the data lines171 may extend to directly connect with the data driver circuit.

The driving voltage lines 172 mainly extend in the transverse directionto cross with the gate lines 121 and transmit driving voltages.

Each driving voltage line 172 includes a plurality of second inputelectrodes 173 b, which extend toward the second control electrodes 124b.

The driving voltage lines 172 overlap with the storage electrode 127 andmay be connected to the storage electrode 127.

The first and second output electrodes 175 a and 175 b are spaced apartfrom each other, the data lines 171, and the driving voltage lines 172.

The first input electrode 173 a and the first output electrode 175 aoppose each other with the first control electrode 124 a interposedtherebetween, and the second input electrode 173 b and the second outputelectrode 175 b oppose each other with the second control electrode 124b interposed therebetween.

The data conductors 171, 172, 175 a, and 175 b may be made of arefractory metal such as molybdenum (Mo), chromium (Cr), tantalum (Ta),or titanium (Ti), or alloys thereof. The data conductors 171, 172, 175a, and 175 b may have a multi-layered structure of a conductive layer(not shown) made of a refractory metal or the like and a conductivelayer (not shown) made of a low resistance material.

Examples of the multi-layered structure include a double-layeredstructure of a lower chromium or molybdenum (or an alloy thereof) layerand an upper aluminum (or aluminum alloy) layer, and a triple-layeredstructure of a lower molybdenum (or molybdenum alloy) layer, anintermediate aluminum (or aluminum alloy) layer, and an upper molybdenum(or molybdenum alloy) layer.

However, instead of the aforementioned materials, the data conductors171, 172, 175 a, and 175 b may be made of various metal and conductivematerials.

Similar to the gate conductors 121 and 124 b, side surfaces of the dataconductors 171, 172, 175 a, and 175 b may also slant at angles in therange of 30° to 80° with respect to a surface of the dielectricsubstrate 110.

The ohmic contact members 163 a, 163 b, 165 a, and 165 b are interposedonly between the underlying first and second semiconductors 154 a and154 b and the overlying data conductors 171, 172, 175 a, and 175 b, andthey reduce contact resistance therebetween.

The semiconductors 154 a and 154 b have exposed portions that areuncovered between the input electrodes 173 a and 173 b and the outputelectrodes 175 a and 175 b and by the data conductors 171, 172, 175 a,and 175 b.

A protective film (passivation layer) 180 is formed on the dataconductors 171, 172, 175 a, and 175 b and the exposed portions of thesemiconductors 154 a and 154 b.

The protective film 180 may be made of an inorganic insulating materialsuch as silicon nitride or silicon oxide, an organic insulatingmaterial, and a low dielectric-constant insulating material.

Here, the organic insulating material and the low dielectric-constantinsulating material may have a dielectric constant of 4.0 or less.Examples of materials formed by performing plasma enhanced chemicalvapor deposition (PECVD) include a-Si:C:O and a-Si:O:F.

The protective film 180 may be made of an organic insulating materialhaving a photosensitive property, and it may have a planar surface.

However, in order to use excellent properties of an organic film andprotect the exposed portions of the semiconductors 154 a and 154 b, theprotective film 180 may have a double-layered structure of a lowerinorganic film and an upper organic film.

A plurality of contact holes 182, 185 a, and 185 b, which expose the endportions 179 of the data lines 171 and the first and second electrodes175 a and 175 b, are formed in the protective film 180, and a pluralityof contact holes 181 and 184, which expose the end portions 129 of thegate lines 121 and the second control electrodes 124 b, are formed inthe protective film 180 and the gate insulating film 140.

A plurality of pixel electrodes 191, a plurality of connecting members85, and a plurality of contact assistant members 81 and 82 are formed onthe protective film 180.

The pixel electrodes 191, the connecting members 85, and the contactassistant members 81 and 82 may be made of a reflective metal such asaluminum, silver, or alloys thereof.

The pixel electrodes 191 are connected to the second output electrodes175 b through the contact holes 185 b, and the connecting members 85 areconnected to the second control electrodes 124 b and the first outputelectrodes 175 a through the contact holes 184 and 185 a.

The contact assistant members 81 and 82 are connected to the endportions 129 of the gate lines 121 and the end portions 179 of the datalines 171 through the contact holes 181 and 182, respectively.

The contact assistant members 81 and 82 may strengthen adhesion of theexposed end portions 179 and 129 of the data lines 171 and the gatelines 121 to external devices, as well as protect the end portions 179and 129.

Partitions 361 are formed above the protective film 180.

The partitions 361 surround the pixel electrodes 191 like a bank todefine an opening 365, and they may be made of an organic or inorganicinsulating material.

Additionally, the partitions 361 may be made of a photo-sensitivematerial including a black pigment. In this case, the partitions 361serve as a light-blocking member and may be formed in a simple process.

An organic light emitting member 370 is formed above the pixelelectrodes 191 in the opening 365 defined by the partition 361.

The organic light emitting member 370 may be made of an organic materialthat emits red, green, or blue light.

The OLED display displays a desired image by using a spatial combinationof the red, green, and blue light emitted by the organic light emittingmember 370.

The organic light emitting member 370 may have a multi-layered structureincluding a light emitting layer (not shown) and an auxiliary layer (notshown) for improving light emitting efficiency of the light emittinglayer.

Examples of the auxiliary layer include an electron transport layer(ETL) (not shown) and a hole transport layer (HTL) (not shown) thatbalance electrons and holes, an electron injecting layer (EIL) (notshown), and an hole injecting layer (HIL) (not shown) that enhanceelectron and hole injection.

A common electrode 270 is formed on the organic light emitting member370.

A common voltage Vss is applied to the common electrode 270, which maybe made of a transparent conductive material such as indium tin oxide(ITO) or indium zinc oxide (IZO).

In the OLED display, the first control electrode 124 a, the first inputelectrode 173 a, and the first output electrode 175 a together with thefirst semiconductor 154 a constitute the switching thin film transistor(switching TFT) Qs, and the channel of the switching TFT Qs is formed inthe first semiconductor 154 a between the first input electrode 173 aand the first output electrode 175 a.

Additionally, the second control electrode 124 b, the second inputelectrode 173 b, and the second output electrode 175 b together with thesecond semiconductor 154 b constitute the driving TFT Qd, and thechannel of the driving TFT Qd is formed in the second semiconductor 154b between the second input electrode 173 b and the second outputelectrode 175 b.

The pixel electrode 191, the organic light emitting member 370, and thecommon electrode 270 constitute the organic light emitting diode LD. Inthe present exemplary embodiment, the pixel electrode 191 and the commonelectrode 270 serve as anode and cathode, respectively. Alternatively,the pixel electrode 191 and the common electrode 270 may serve ascathode and anode, respectively.

The storage electrode 127 and the driving voltage lines 172 overlap witheach other to constitute storage capacitors Cst.

The OLED display according to the present exemplary embodiment displaysan image by emitting light in the upward direction with respect to thedielectric substrate 110.

In other words, the reflective pixel electrode 191 and the transparentcommon electrode 270 may be utilized in a top emission type of OLEDdisplay where an image is displayed in the upward direction with respectto the dielectric substrate 110.

When the semiconductors 154 a and 154 b are made of polysilicon, thesemiconductors 154 a and 154 b include intrinsic regions (not shown)facing the control electrodes 124 a and 124 b and extrinsic regions (notshown) interposed between the intrinsic regions.

In this case, the extrinsic regions are electrically connected to theinput electrodes 173 a and 173 b and the output electrodes 175 a and 175b, and the ohmic contact members 163 a, 163 b, 165 a, and 165 b may beomitted.

Additionally, the control electrodes 124 a and 124 b may be disposedabove the semiconductors 154 a and 154 b. In this case, the gateinsulating layer 140 is also disposed between the semiconductors 154 aand 154 b and the control electrodes 124 a and 124 b.

Further, the data conductors 171, 172, 173 b, and 175 b are disposedabove the gate insulating layer 140 and are electrically connected tothe semiconductors 154 a and 154 b through a contact hole (not shown)formed through the gate insulating layer 140.

Alternatively, the data conductors 171, 172, 173 b, and 175 b may bedisposed below the gate insulating layer 140 and be electricallyconnected to the semiconductors 154 a and 154 b.

A sealing member 390 is formed above the common electrode 270.

The sealing member 390 encapsulates the organic light emitting member370 and the common electrode 270 to prevent penetration of moisture oroxygen from the outside.

The sealing member 390 may be made of an insulating material such asglass or plastic, or a resin in a shape of a film.

Next, a display device according to another exemplary embodiment of thepresent invention will be described in detail below with reference toFIG. 9, FIG. 10, FIG. 11, and FIG. 12.

FIG. 9 is a view showing a layout of a display device according to anexemplary embodiment of the present invention, and FIG. 10, FIG. 11, andFIG. 12 are cross-sectional views taken along lines X-X, XI-XI, andXII-XII of FIG. 9, respectively.

A plurality of gate lines 121, which include a first control electrode124 a, and a plurality of gate conductors, which include a plurality ofsecond control electrodes 124 b, are disposed on a dielectric substrate110.

Each gate line 121 includes a wider end portion 129.

The second control electrodes 124 b include a storage electrode 127extending therefrom.

A gate insulating layer 140 is formed above the gate conductors 121 and124 b.

A plurality of first and second island-shaped semiconductors 154 a and154 b are formed on the gate insulating film 140, and a plurality offirst pairs of ohmic contact members 163 a and 165 a and a plurality ofsecond pairs of ohmic contact members 163 b and 165 b are formed abovethe first and second semiconductors 154 a and 154 b, respectively.

A plurality of data conductors, which include a plurality of data lines171, a plurality of driving voltage lines 172, and a plurality of firstand second output electrodes 175 a and 175 b, are formed above the ohmiccontact members 163 a, 163 b, 165 a, and 165 b and the gate insulatinglayer 140.

Each data line 171 includes a plurality of first input electrodes 173 a,which extend toward the first control electrode 124 a, and a wider endportion 179 for connection to other layers or an external drivingcircuit.

Each driving voltage line 172 includes a plurality of second inputelectrodes 173 b, which extend toward the second control electrodes 124b.

The first and second output electrodes 175 a and 175 b are spaced apartfrom each other, the data lines 171, and the driving voltage lines 172.

A protective film 180 is formed on the data conductors 171, 172, 175 a,and 175 b and the exposed portions of the semiconductors 154 a and 154b. A plurality of contact holes 182, 185 a, and 185 b, which expose theend portions 179 of the data lines 171 and the first and second outputelectrodes 175 a and 175 b, are formed in the protective film 180.Additionally, a plurality of contact holes 181 and 184, which expose theend portions 129 of the gate lines 121 and the second control electrodes124 b, are formed in the protective film 180 and the gate insulatingfilm 140.

A plurality of pixel electrodes 191, a plurality of first and secondconnecting members 85 and 86, and a plurality of contact assistantmembers 81 and 82 are formed on the protective film 180.

The pixel electrodes 191 are connected to the second output electrodes175 b through the contact holes 185 b, and the connecting members 85 areconnected to the second control electrodes 124 b and the first outputelectrodes 175 a through the contact holes 184 and 185 a.

Partitions 361 are formed above the protective film 180.

An organic light emitting member 370 is formed above the pixelelectrodes 191 in the opening 365 defined by the partition 361.

A common electrode 270 is formed on the organic light emitting member370.

A sealing member 390 is formed above the common electrode 270.

However, unlike the display device in FIGS. 6 to 8, according to thepresent exemplary embodiment, the pixel electrode 191 is made of atransparent conductive material such as indium tin oxide (ITO) or indiumzinc oxide (IZO), and the common electrode 270 is made of a reflectivemetal such as calcium (Ca), barium (Ba), magnesium (Mg), aluminum (Al),or silver (Ag).

Accordingly, the display device according to the present exemplaryembodiment displays an image by emitting light in the downward directionwith respect to the dielectric substrate 110.

In other words, the transparent pixel electrode 191 and the reflectivecommon electrode 270 are utilized in a bottom emission type of OLEDdisplay where the image is displayed in the downward direction withrespect to the dielectric substrate 110.

In addition, unlike the display device in FIGS. 6 to 8, the displaydevice according to the present exemplary embodiment further includes anassistant electrode line 122 that extends in parallel with the gatelines 121.

The assistant electrode line 122 includes a protrusion 123 protrudingtherefrom in the transverse direction, and serves to transmit a commonvoltage.

The assistant electrode line 122 may be made of the same material and inthe same layer as that of the gate lines 121 or the data lines 171, andit may extend in parallel with the gate lines 121.

Additionally, a contact hole 186 in the protective film 180 exposes theprotrusion 123 of the assistant electrode line 122.

The second connecting member 86 is connected to the protrusion 123 ofthe assistant electrode line 122 through the contact hole 186.

The common electrode 270 is connected to the protrusion 123 of theassistant electrode line 122 through a contact hole 366 and the secondconnecting member 86.

Since the common electrode 270 is connected to the protrusion 123 of theassistant electrode line 122, it may be possible to stably supply thecommon voltage to the common electrode 270 even when the commonelectrode 270 is made of a transparent or semi-transparent conductivematerial that has a relatively high resistance.

Consequently, it may be possible to supply a substantially uniformcommon voltage to the entire region of the common electrode 270 withoutcausing a voltage drop.

According to exemplary embodiments of the present invention, it may bepossible to discharge charges accumulated on the common electrode duringthe display device manufacturing process, thereby enhancing reliabilityof the display device.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A display device, comprising: a substrate; a first voltage linedisposed on the substrate; a first electrode pad to transmit a drivingvoltage to the first voltage line; a first transistor connected to thefirst voltage line; a first electrode connected to the first transistor;a second electrode opposing the first electrode; a light emitting memberdisposed between the first electrode and the second electrode; and asecond electrode pad disposed on the substrate, the second electrode padto transmit a second voltage to the second electrode, wherein the secondelectrode pad and the first electrode pad are exposed at a side of thesubstrate, and wherein end portions of the exposed second electrode padand the exposed first electrode pad coincide with edges of thesubstrate.
 2. The display device of claim 1, wherein at least one sideof each of the second electrode pad and the first electrode pad includesa first portion that is exposed at the side of the substrate and asecond portion that is not exposed at the side of the substrate; andwherein a distance between the second portion of the second electrodepad and the side of the substrate or a distance between the secondportion of the first electrode pad and the side of the substrate is 25μm or less.
 3. A method of manufacturing a display device, comprising:forming a plurality of first signal lines, a driving first voltage lineincluding a first electrode pad, a plurality of second signal lines, anda second electrode pad on a substrate; forming a first connecting memberbetween the first electrode pad and the second electrode pad; forming aprotective film and a first electrode on the first signal lines, thefirst voltage line, and the second signal lines; forming a lightemitting layer on the first electrode; forming a second electrode on thelight emitting layer; forming a sealing member on the second electrode;and cutting the substrate such that the first connecting member isexposed at a side of the substrate, wherein end portions of the exposedfirst connecting member coincide with edges of the substrate.
 4. Themethod of claim 3, wherein cutting the substrate includes cutting thefirst connecting member.
 5. The method of claim 3, wherein the firstelectrode pad comprises the same material as the second signal lines. 6.The method of claim 3, wherein the second electrode pad comprises thesame material as the first signal lines.
 7. The method of claim 6,wherein the second electrode is transparent.
 8. The method of claim 7,wherein the first connecting member comprises the same material as thesecond electrode.
 9. The method of claim 6, wherein the first electrodeis transparent.
 10. The method of claim 9, wherein the first connectingmember comprises the same material as the first electrode.
 11. Themethod of claim 3, wherein the second electrode pad comprises the samematerial as the second signal lines.
 12. The method of claim 11, whereinthe first connecting member comprises the same material as the secondsignal lines.
 13. The method of claim 3, further comprising: forming afirst signal line shorting bar that connects the plurality of firstsignal lines to each other; and forming a second signal line shortingbar that connects the plurality of second signal lines to each other.14. The method of claim 13, further comprising: forming a secondconnecting member that connects the first electrode pad to the firstsignal line shorting bar or the second signal line shorting bar.
 15. Themethod of claim 13, further comprising: forming a second connectingmember that connects the second electrode pad to the first signal lineshorting bar or the second signal line shorting bar.
 16. The method ofclaim 14, wherein cutting the substrate comprises cutting the secondconnecting member.
 17. The method of claim 15, wherein cutting thesubstrate comprises cutting the second connecting member.
 18. The methodof claim 3, further comprising: forming a discharge member on thesubstrate and connected to the first connecting member.
 19. The methodof claim 14, further comprising: forming a discharge member on thesubstrate and connected to at least one of the first connecting memberand the second connecting member.
 20. The method of claim 15, furthercomprising: forming a discharge member on the substrate and connected toat least one of the first connecting member and the second connectingmember.
 21. The method of claim 18, wherein the discharge member isconnected to a ground potential.
 22. The method of claim 19, whereincutting the substrate comprises removing the discharge member.
 23. Themethod of claim 3, wherein cutting the substrate comprises removing thedischarge member.